import cv2 as cv
# 指定倍数
img = cv.imread('image.jpg')
res1 = cv.resize(img, None, fx=0.5, fy=0.5, interpolation=cv.INTER_AREA)  
# 或者：指定大小
height, width = img.shape[:2]
res2 = cv.resize(img, (int(1.5 * width), int(1.5 * height)), interpolation=cv.INTER_CUBIC)  
cv.imshow('res1', res1)
cv.imshow('res2', res2)
k = cv.waitKey(0)
cv.destroyAllWindows()